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A relative newcomer to New Jersey's inland waters, walleyes are making a big splash in Swartswood Lake. Walleyes are considered a coolwater fish, with temperature preferences between those of coldwater fishes like trout, and warmwater fishes such as largemouthbass and sunfish. They also like slightly turbid water conditions and rocky bottoms with drop-offs. Over ten years ago the Division's Hackettstown Hatchery began successfully rearing this non-native gamefish for introduction in the newly created Monksville Reservoir. Later refinements in our hatchery production made it possible to expand our stocking efforts into other suitable waters including Swartswood Lake, Lake Hopatcong, Greenwood Lake, Delaware River, and Canistear Reservoir.

Since 1992, the Division has been stocking walleye fry and fingerlings in Swartswood Lake, Sussex County. This 494 acre lake not only has favorable walleye habitat, but also good forage fish species like alewives (herring) and yellow perch. Over the first seven years more than 165,000 walleyes were stocked, but anglers provided little feedback regarding the walleye catch. Could it be that the fishery just wasn't developing as expected or were the walleyes simply outsmarting the anglers? In the spring of 1999 we set out to investigate the status of Swartswood's walleye population. Our objective was to estimate the size of the existing walleye population using a technique called mark-recapture. Intensive sampling (using trap nets and electrofishing at night) was conducted over a 13 day period in late March-early April, when walleyes move into shallow water in search of spawning sites. As walleyes were captured they were examined and marked by clipping a portion of their tail fin, then immediately released back into the lake. At the conclusion of the sampling period we applied a statistical procedure, based upon the number of marked fish recaptured, to estimate the size of the population.

A total of 242 walleyes - ranging in size from 11.7 to 24.3 inches - were caught, with the largest (a female laden with eggs) weighing in at 6.3 lbs. Only thirteen of these fish were captured more than once. This data yielded a population estimate of approximately 2,000 walleyes over 12 inches, just what we had expected (and hoped) to find in this lake.

So walleyes are alive and well in Swartswood Lake. As to the lack of feedback from anglers, I venture to say this good-fighting and fine-eating sportfish has either been elusive, or their catch is a closely guarded secret among successful anglers. So visit Swartswood Lake and try to unlock the secret to this lake's new and exciting fishery.